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    CARP and ESXi: trick to get multiple MACIDs working?

    Scheduled Pinned Locked Moved HA/CARP/VIPs
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    • Z
      zippydan
      last edited by

      I've cross-posted this to the Virtualization subforum as well, since it involves both topics.  Hopefully that is not against the rules.

      I have a cable modem connection with multiple static IPs.  The modem is in bridge mode.

      Normally I would just assign one main IP to the pfsense interface, and then assign the other static IPs as virtual IPs to the same interface.

      However apparently this ISP requires that each static IP be associated with a single unique MACID.

      It seems that in this situation that CARP is the tool for ensuring that each Virtual IP has a different MACID.

      It isn't working for me.

      I've followed the directions here: https://doc.pfsense.org/index.php/CARP_Configuration_Troubleshooting#Hypervisor_users_.28Especially_VMware_ESX.2FESXi.29 and enabled Promiscuous mode and allowed Mac Address Changes and Forged Transmits.

      The connection still behaves as if I've assigned multiple IPs to the same MACID (which is to say it doesn't work).

      Of course I've reset the modem several times and it makes no difference.

      It seems to me that either CARP is not working as it should on the pfsense side, or there is an underlying compatibility problem with ESXi and it is not allowing multiple MACiDs to exist on the same interface, and therefore is not passing on those CARP MACIDs to the modem.

      Anyone have any advice for how I should proceed from here?

      Running pfsense 2.3.2 on ESXi 6.0.

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      • jimpJ
        jimp Rebel Alliance Developer Netgate
        last edited by

        I removed the second post, cross-posting identical (or nearly so) messages is not something we like to see.

        CARP is not going to accomplish what you want there. The requests have to originate from different MAC addresses and the only way for that to happen is to use additional interfaces. You can link up several more virtual NICs in ESX to the same WAN segment, but that's really ugly as only one of them will actually be used for outgoing traffic.

        Depending on what you're trying to accomplish, it might be best to bridge a local segment to WAN and allow devices needing those extra outside IP addresses to pull them directly.

        That or convince the ISP to route them to you properly instead of requiring multi-MAC DHCP nonsense…

        Remember: Upvote with the 👍 button for any user/post you find to be helpful, informative, or deserving of recognition!

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        • Z
          zippydan
          last edited by

          MACIDs are fairly trivial to spoof.  Why not offer an option to specify the MACID for a virtual IP within the pfSense webGUI?  To me, this seems like the most elegant, straightforward and simple solution.

          This is a national ISP and I'm using their standard "business-class" cable service.  They aren't going to make any special exceptions for me (I've tried, multiple times, escalating the case as far as it would go).  And upgrading to a more expensive service is not an option either.  And there are no viable competitors that offer service in the same area, especially not at the speeds I need.

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          • DerelictD
            Derelict LAYER 8 Netgate
            last edited by

            So we all know, which ISP is doing this? Seems like something Comcast would come up with.

            Chattanooga, Tennessee, USA
            A comprehensive network diagram is worth 10,000 words and 15 conference calls.
            DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
            Do Not Chat For Help! NO_WAN_EGRESS(TM)

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            • jimpJ
              jimp Rebel Alliance Developer Netgate
              last edited by

              @zippydan:

              MACIDs are fairly trivial to spoof.  Why not offer an option to specify the MACID for a virtual IP within the pfSense webGUI?  To me, this seems like the most elegant, straightforward and simple solution.

              Because it's not possible do that.

              Remember: Upvote with the 👍 button for any user/post you find to be helpful, informative, or deserving of recognition!

              Need help fast? Netgate Global Support!

              Do not Chat/PM for help!

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              • DerelictD
                Derelict LAYER 8 Netgate
                last edited by

                MACIDs are fairly trivial to spoof.

                Maybe for the one for the interface itself. Not several on one interface.

                Chattanooga, Tennessee, USA
                A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                • 8
                  88fingerslukee
                  last edited by

                  @jimp:

                  I removed the second post, cross-posting identical (or nearly so) messages is not something we like to see.

                  CARP is not going to accomplish what you want there. The requests have to originate from different MAC addresses and the only way for that to happen is to use additional interfaces. You can link up several more virtual NICs in ESX to the same WAN segment, but that's really ugly as only one of them will actually be used for outgoing traffic.

                  Depending on what you're trying to accomplish, it might be best to bridge a local segment to WAN and allow devices needing those extra outside IP addresses to pull them directly.

                  That or convince the ISP to route them to you properly instead of requiring multi-MAC DHCP nonsense…

                  Sorry to drag up an old thread but the following article says that this IS possible:

                  https://doc.pfsense.org/index.php/What_are_Virtual_IP_Addresses

                  Is the article wrong?

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                  • jimpJ
                    jimp Rebel Alliance Developer Netgate
                    last edited by

                    The firewall sends out traffic from the interface MAC. It can receive traffic using the CARP MAC.

                    It won't satisfy all of the requirements for this ISP if it requires both.

                    Remember: Upvote with the 👍 button for any user/post you find to be helpful, informative, or deserving of recognition!

                    Need help fast? Netgate Global Support!

                    Do not Chat/PM for help!

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